Toggle trigger mechanism



2 Sheets-Shea?l l E. L. HARDGRAVE TOGGLE TRIGGER MECHANISM hHa migra/1reATTORNEY umlkmkln..

Sept. 2O, 1955 Filed Feb. 2o, 1953 Sept- 20, 1955 E. HARDGRAVE TOGGLETRIGGER MECHANISM 2 Sheets-Sheet 2 Filed Feb. 20, 1955 INVENTOR E@rZL.H-ara,7ra7fe TTORNEY United States This linvention lrelates to anovel trigger mechanism 'fora bolt-faction rifle `andfrnoreyparticularly toa trigger :mechanism "provided'with -a -novel set `unitwhereby -the trigger mayfbeeasilyset=to release-the sear after'only as'lig'ltimovement ofthe triggeriand which set unit automaticallydisengages'when thetrigger-is pulled-or moved `lto `a Sear Vreleasingposition allowingthe trigger to return y'to :a full'single stage withalmaximum contact between the engaging surfaces 'of the Sear-andvtrigger and from Vwhich position thetrigger may thereafter be againpulled either from said lfu'll single stage position or, by a simpleoperation of the set unit, from a set position.

yAlnotherfobject of the-invention is vto-provide a triggerYm'e'chanisn'l -wherein fthe tensionof 'an-adjustable tension springwill=maintain the 'setfunit in an operative position until vtension-on:the spring lis `released by a pull exerted on the trigger 4'andwhereupon the set unit will automatically A'move to a `released orinoperative position to permit returnrof the -trigger to a full singlestage with maximumcontact lwith the sear after-release ofthe sear.

A further object of the invention is to vprovide a trigger mechanism?having a toggle joint type unitrforrning the set unit thereof andwhichirnay be readily adjusted for varying the extent of pull requiredto move-the trigger to a sear releasing position froma set position.

`Another object of the invention istoprovide a trigger mechanism having-a novel 'construction of housing and frame wherebya portion of thelmechanism may be economically constructed from sheet metal.

'Various other objects and advantages of the invention will `hereinafterbecome more ffully apparent from the following description ofthev'drawings, illustrating-apresently fpreferred embodiment thereof,and wherein:

Figure Yl is a vertical sectional View, partly in side elevationvshowing a trigger mechanism lmounted V-on the receiveriportionlof-a`bolt action rfleand with the trigger in afull single stage position andhaving maximunrcontact with asear;

4Figure 2 is a View similar to Figure -1 showing the sear in a releasedposition;

v'Figure l3 is a top plan View of the Vtrigger mechanism removed -fromthe receiver;

' `Figure-4 is anenlarged transverse sectionalview ofthe trigger:mechanism taken substantially falong a `plane as indicated by the -line44of Figure -l;

Figure 5 is an enlarged longitudinal sectional'view of the triggermechanism 'taken substantially alonga plane as indicated by the -line5--5 Vof fFigure l;

Figure 61is a fragmentaryvertieal sectional viewtakensubstantiallyfalong a `plane as indicated `=by the line 6 6 of Figure.5, :and

Figure 7 -is la fragmentary. side elevational `view .of a portion lofthe trigger mechanism.

rReferring.more specifically to lthe drawings, =forthe;pur pose `of morexclearly illustrating the application and use of :the novelYtriggermechanismD designated generally 10 and Icomprising theinvention, a portion of the receiver 11 of a boltvaction 4rifle isillustrated ;in Figures l and 2 arent O ist) lCe

2 including a'portionof'the-rilie'bolt"12'having a sear engaging 'lug 13vdepending downwardly therefrom.

The trigger mechanism 10 includes a housing, designated generally 14whichis formed fromra'folde'd and cut strip of sheet metal having spacedsubstantially parallel sides 15, as best illustrated in Figure 3, 'whichare connectedby spaced rivets 16, `17 and 18. The strip forming thehousing `ll includes adownwardly depressed ltransverse portion 19extending between andformed integral with complementary portions of the'upper-edgesf the sides E15 and which is provided at its rear end with adepending extension n`2i) the lower end "21 of Vwhich -is lbentforwardlyaround therivet or l`fasteningl`7 lThe sides l'S, forwardly of -the part19, are provided withicorresponding upwardly extending portions '522having aligned apertures for receiving a pivot pin 23 .by which thehousling 154i is ypivotally connected to theireceiver 11, neartheforward endfof said housing. The lside .walls 'I'Slat their forward-ends .are provided with -inturned portions forming a-front wall 214 andatftheir bottoms are providedwith inturned extensions,adjaeentthe-'front wall 24, forminga bottom portion 25, which combineswithsaid front -wall l24ftoforrn-a pocket attheiforward end-oftheihousing `fli4l lin which is seated the lower'endfof a compressionspring .26, the =upper end 'of which -is seated -in a downwardlyLopening 'socket l27of-the receiver Il, for urgingthe-housing '14 to:rock about the pivot l23 to `maintain -the 'rear :portion yof -the`fhousing iin la raised position against the receiver.

A trigger 28 has an upper portion -`29 which vextends-upwardlylinto-.the housing 1'4 'between itssides l5, behind the'stripi219. Apivotfpin-S() `extends through the trigger .portion `29 .and .issupported fin the sides 15 behind the -lowerstrip portion 2lforfswingably mountingfthe trigger 28 for forward and rearward swingingvmovement-of the upperandflowerends thereof. The lower end 3l-ofthe`triggerZS forms a 'linger Vengaginglportion@of conventional tconfiguration.

A :frame 32, which Yis :formed Ifrom a single `strip f 'sheet :metalfolded back .upon nitself intermediate of vits ends, has portionsfthereof `located .adjacent its 'terminals .33 which -straddle anintermediate fportionl34 fof 'the ltrigsger 3-1 and which rare 4securedLthereto l'by Ysuitable fasten- =ings such as the Vrivets `35. Therintermediate lportion `of the'istrip forming the yframe 32 defines atransverse end wall 36 which is spaced from lthe .triggervp'ortionl AA4.rivet :37 extends `across fthe 'frame 32 :and :is *supported thereby:between the trigger portion 34 and end wall 36. "A spring sea't v3:8Iis formed by substantially U-shaped .strips :having leg zportions fofdifferent Tlengths .the termi- Anals of which 'are turned Voutwardly andAback upon themselves to I'form hook-s 39. The springseat 385is disposedin the frame S2 between its end `wall '36 fand the rivet 37 Tand "thehook 39 -of the longer leg 'thereof engages D 4over the upperedge of theend `wall-'36 while the hook 390i thershorter-leg engages-over the rivet"37, `to support the spring seat 3S lin an upwardly `opening position in:the frame 32. The Vintermediate `or-bight portion ofthespring seat 58,constituting the Vbottom thereof, Vis;provided with a threadedopening 4)to adjustably receive ascrew 4.11 which y.extends threadedlytherethrough and which Lhasa head l42 at lits upper end disposed `withinAthe springseat lforming. an adjustable perch or 'springstop `'ifrfjarnbnut 43 threadedly engages the lower portion ofthe screw 41 andbearsagainst the underside .of the springseatibottom toretain thespring stop42in different adjusted tpositions.

Y A sear 44 Ais turnably mounted lin the upper rear'part of the housing14 onfapivot pin 45which issupported by .the Asides u15. The vsear 44 isshown in its normal posi- 'tion 2in vFigure l -and as :thus rdisposedhas an upwardly extending rearwardly 'facing shoulder 4'6 which engagesthe forward face of the lug 13 to retain the firing mechanism,associated withY the bolt 12, in a retracted cocked position. As thusdisposed, the sear has a downwardly facing shoulder 47 at the rearthereof which engages against the rear rivet 18 to prevent the sear fromrotating clockwise beyond its position of Figure l. Forwardly of thepivot 45, the sear 44 is provided with a concavely rounded downwardlyand rearwardly opening notch 48, and forwardlyY of said notch 48 andthereabove, the sear 44 is provided with a` downwardly facing shoulderor surface 49 which extends to the forwardmost extremity of the sear.

The housing sides adjacent their rear ends and bottoms are cut and bentinwardly and the inturned portions are notched to cooperate and form anapertured spring abutment 50, as best seen in Figure 4, which isdisposed above the spring seat 38. An apertured spring guide 51 is heldseated against the underside of the abutment by the upper end of a mainexpansion coil spring 52, which extends downwardly into the spring seat38 and which is supported at its lower end on the adjustable spring stop42. A smaller inner expansion coil spring 53 has its lower end bearingon the spring stop 42 and extends upwardly therefrom through the alignedapertures of the spring guide 51 and abutment 50. A rigid rod 54 isdisposed in the upper portion of the spring 53 and likewise extendsthrough the parts 50 and 51. The rod 54 has a crossbar 55 at its upperend against which the upper end of the spring 53 bears to maintain thecrossbar 55 seated in the notch 48 of the Sear 44, so that said sear isnormally turned clockwise by the tension of the spring 53 to itsposition of Figure l from its position of Figure 2.

A block 56 has a restricted inner end 57 which fits between theterminals 33 of the frame 32 and is secured thereto by a fastening 58,as best seen in Figures 5 and 6. A pin 59 seats in opposed recesses 60formed in the abutting faces of the trigger portion 34 and block 56 tocooperate with the fastening 58 to maintain the block 56 rigidlyrelatively to the frame 32. The outer portion of the block 56 has athreaded bore 61 extending from top to bottom therethrough. The block 56is split as seen at 62 from its outer end inwardly to the threaded bore61 so that said bore can be expanded when a socket member 63 is threadedupwardly into the bore 61 whereby said socket member 63 will befrictionally gripped and maintained in an adjusted position in the block56. The socket member 63 has an upwardly opening socket 64 provided witha ared upper end 65.

The adjustable socket member 53 constitutes a part r of the toggle jointset unit, designated generally 66, which includes a lever, designatedgenerally 67, having spaced substantially parallel sections 68, thelower portions of which straddle the block 56 and/or the frame terminals33, as best illustrated in Figure 5. The lower ends of said sections 68are connected by a crosspiece 69, as seen in Figure 6, which is disposedbelow the block 56 and to the underside of which is secured a thumbpiece 70 having a roughened outer surface. The upper portions of thelever sections 68 are loosely disposed in the bottom part of the housing14 beneath and spaced from the part 21 and are pivotally mounted thereinon a pivot pin 71 which is supported by the sides 15. A spring 72 has apart thereof coiled about the pivot 71 between the lever sections 68 andis provided with an upwardly extending intermediate portion 73 whichbears against the forward end of the abutment 21, which provides a fixedperch for the spring 72. The terminals 74 o fathe spring 72 are bentoutwardly and around the forward edges of the lever sections 68, belowthe pivot 71, for urging the lever 67 to swing counterclockwise orrearwardly, as seen in Figures l and 2, about its pivot 71. The togglejoint 66 also includes a pin 75 forming a second lever thereof, theenlarged upper end of which is loosely disposed between intermediateportions of the lever sections 68 and swingably connected thereto bytrunnions 76. The restricted lower end of the lever pin 75 terminates ina tapered free end 77 which seats for fulcmming movement in the socket64 including the beveled upper end 65 thereof. Thus, the socket 64, 65and the tapered lever end 77 constitute the bottom pivot of the togglejoint 66, the pivot 71 constituting the top pivot thereof, and thetrunnions 76 which pivotally connect the upper portion of the lever pin75 to the intermediate portion of the lever 67 form the intermediatepivot of the toggle joint.

The upper ends of the lever sections 68 are beveled to form terminalportions 78 which are swingable into engagement with the abutment 21 tolimit clockwise swinging movement of the lever 67 to but not beyond itsdotted line position of Figure l. Y

Corresponding ends of the shafts or pivots 30 and 45 are grooved as seenat 79 to receive the notched ends of a spring latch strip 80 which bearsagainst the outer surface of one of the sides 15 for detachablyretaining said shafts 30 and 45 in applied positions in the housing 14.A slotted latch strip 81 similarly engages a groove 82 of the pivot pin71, for the same purpose.

The toggle joint set 66 is illustrated in an inoperative or brokenposition in Figure l and with the intermediate pivot 76 thereof disposedto the right of the top and bottom pivots. When thus disposed, the upperend of the upper trigger portion 29, which forms a sear engaging part orsurface 83, fully seats against the sear shoulder 49 from its inner toits outer end in a full single stage position of the trigger mechanismwhere maximum contact exists between the trigger portion 83 and searnotch 49, so that maximum swinging movement of the trigger 28 in acounterclockwise direction about its pivot 30 from its position ofFigure l toward its position of Figure 2 is necessary before the triggerportion 83 releases the sear. When release of the sear occurs, the sear44 will be swung counterclockwise to its position of Figure 2 by theforward thrust on the lug 13 which is provided by the firing mechanismof which said lug forms a part. The main spring 52 resists this swingingmovement of the trigger 2S to a sear releasing position and the triggerpull may obviously be varied by adjustment of the spring seat 42. Theweak spring 53 is compressed when the scar 44 is released and swungcounterclockwise to its position of Figure 2 and the bar 55 rides in thenotch 48 as the spring 53 and guide rod 54 are displaced downwardlythrough the parts 50 and 51. Thereafter, when the lug 13 has again beenmoved rearwardly the weak spring 53 will expand turning the sear 44clockwise back to its position of Figure l and so that the strongerspring 52 may thereafter swing the trigger 28 clockwise to re-engage thesurface 83 fully beneath the sear shoulder 49 in its full single stage,full line position of Figure l.

If it is desired to position the trigger 28 in a set position so only aslight pull or movement thereof will be required to release the sear 44,the thumb piece 70 is engaged to swing the toggle lever 67 clockwiseabout its pivot 71 from its full line to its dotted line position ofFigure l. This movement causes the intermediate pivot 76 to move fromright to left across the dead center of the top and bottom pivots of thetoggle joint and results in the toggle joint assuming an extendedoperative position. In this extended dotted line position of the togglejoint, the dis- 7 tance between the end pivots thereof is increased andas the upper pivot 71 is stationary, the lower pivot 65, 77 is displaceddownwardly so that the trigger 28 and frame 32 are rockedcounterclockwise about the trigger pivot 30 and the main spring 52 isadditionally compressed. Accordingly, the trigger 28 is displaced to itsdotted line position of Figure l in which set position only a smallportion of the trigger end 83 engages the outer end of the sear shoulder49. The tensioned main spring 52 exerts an upward thrust on the bottompivot of the toggle joint and said spring is of suflicient strength toovercome the tension of the spring 72 to thus prevent the intermediatepivot 7 6 from moving from left to right back across the dead center ofthc top and bottom toggle joint pivots, to thus maintain the trigger 28in its set, dotted line position of Figure 1. When the trigger portion31 is engaged and a rearward pressure exerted thereon initial rearmovement of the trigger, counterclockwise about its pivot 30, willrelease the upward pressure on the bottom pivot of the toggle jointallowing the spring 72 to snap the middle toggle pivot 76 from left toright across the top and bottom toggle pivots to thus swing the lever 67back to its full line position for breaking the toggle joint to renderthe set 66 inoperative. This will usually occur before the trigger end83 disengages the sear shoulder 49. Accordingly, when the triggerthereafter re-engages the sear it wiil assume a full single stageposition with maximum contact between the parts 83 and 49, as shown infull lines of Figure l, and the lever 67 will again have to be swungmanually clockwise from right to left about its pivot 7i to return thetrigger mechanism to a set position where a slight trigger movement willbe suicient to release the sear.

Various modications and changes are contemplated and may obviously beresorted to, without departing from the spirit or scope of the inventionas hereinafter defined by the appended claims.

i claim as my invention:

1. A triggermechanism of the character described comprising a housing, asear pivoted to said housing, said sear having a shoulder spaced fromthe sear pivot, a trigger pivoted to the housing having a Sear engagingportion spaced from the trigger pivot and engaging the shoulder of thesear for holding the sear in an operative tiring mechanism cookingposition, a main spring engaging said housing and trigger and urgingsaid sear engaging trigger portion into full engagement with the Searshoulder, and a toggle joint set including a first lever and a secondlever, said first lever having one end pivoted to the housing, saidsecond lever having one end pivoted on a part of the trigger, the otherend of said second lever being pivotally connected to an intermediateportion of the first lever and constituting an intermediate pivot of thetoggle joint levers, said intermediate pivot being movable in onedirection across a line extending between said end pivot of the iirsttoggle joint lever and the iirst mentioned pivot of the second togglejoint lever from a broken to an extended operative position of thetoggle joint set for rocking the trigger on its pivot against said mainspring for moving the trigger toward a released position and for movingthe sear engaging trigger portion into a position in partial contactwith said sear shoulder.

2. A trigger mechanism as in claim 1, and abutment means limitingswinging movement of the toggle joint set toward an extended, operativeposition.

3. A trigger mechanism as in claim 1, and a toggle joint spring carriedby said toggle joint and urging the toggle joint to a broken positionwhereby movement of the trigger to a sear releasing position willrelieve the pressure on the extended toggle joint to permit said togglejoint spring to move said toggle joint to a broken, inoperativeposition, said toggle joint spring being weaker than said main spring.

4. A trigger mechanism as in claim 1, the first lever of the togglejoint having an extension projecting below said intermediate pivot andforming an actuating lever for manual movement of the toggle joint toand from extended and broken positions.

5. A trigger mechanism as in claim 1, and means adjustably locating thefirst mentioned pivot of said second toggle joint lever for varying thespacing between the toggle joint end pivots to adjust the extent ofpartial contact of said sear engaging trigger portion with the searshoulder when the toggle joint is in an extended posinon.

6. A trigger mechanism as in claim 1, said trigger having a frameforming a part thereof including a rearwardly extending portion, thetrigger pivot being disposed between said frarne and the Sear engagingtrigger portion, and one end of said main spring bearing on said rearframe portion.

7. A trigger mechanism as in claim 6, said frame including a forwardportion extending forwardly from the trigger, an adjustable fulcrum seatmounted in said forward frame portion for adjustment toward and awayfrom said end pivot of the iirst toggle joint lever and forming a seatconstituting a part of the rst mentioned pivot of the second lever ofthe toggle joint.

8. A trigger mechanism as in claim 7, said housing having an aperturedseat for said main spring, a sear spring having one end disposed in saidmain spring and seated therewith against the frame and having anopposite end extending through the spring seat of the housing and towardthe Sear, a rigid guide stem disposed in said last mentioned sear springend and having an outer end defining a head against which the lastmentioned end of the sear spring engages, and said sear having aconcavely rounded recessed portion against which the stem head slidablybears, said recessed sear portion being disposed between the searshoulder and the sear pivot, and said sear spring being compressed bymovement of the sear to a ring mechanism releasing position and reactingto return the sear to a cocked tiring mechanism engaging position and toreturn the sear shoulder to a trigger engaging position.

9. A trigger mechanism as in claim 1, said housing being formed from afolded piece of sheet metal defining spaced side walls between whichportions the sear and trigger are pivotally mounted, said housing havingan open top through which a portion of the sear extends and an openbottom from which a portion of the trigger depends.

No references cited.

